This invention relates to a media folder for carrying folded sheet material such as choral composition, periodic newsletters, reports and other sheets that are frequently relocated or replaced in the folder. Specifically, the invention relates to improvements in the structural design disclosed in my U.S. Pat. No. 4,840,407 entitled SHEET MUSIC BINDER, issued Jun. 20, 1989.
In the above-mentioned 4,840,407 patent, I illustrate a center post assembly or rotor which supports rubber bands on pins at the ends of the rotor. Folded sheet music is opened and one side edge is slipped under one strand of a rubber band until the fold in the center of the sheet music aligns with the band. Thereafter, that folded sheet is fully supported by the one strand. Other sheets are similarly arranged on the rotor until all sheet music for a particular program is in place and ready to be used by the individual of the choral group. In actual use, a few problems were discovered in the patented design, however, and it is primarily those problems which the present invention is designed to overcome. When sheets were slid out from beneath their particular strand during removal from the binder, friction between the sheet face and the rubber band would tend to twist and wind up the band, sometimes causing an end of the twisted band to slip off its pin or pins. In so doing, the sheet and its band would detach from the rotor and the rubber band would then have to be removed edgewise from the sheet. The band would then have to be restretched and replaced on the pins from which it was displaced. If several adjacent bands were accidentally displaced, it was not uncommon that a replaced band could be unintentionally placed on a pair of pins that were not directly opposite one another, and that rubber band and sheets later held thereby would be slightly skewed rather than aligned parallel to the rotor.
A further potential for difficulty was in the fact that the rotor of the ""407 patent was journaled on mounting brackets which were held by double-sided self-adhesive sheet material to the binder. With age and sometimes due to storage of the binder in an area of increased temperature, there existed the possibility of reduction in the gripping power of the adhesive. Furthermore, if any of the rotor parts ever required replacement, for example, if damage occurred that caused some of the pins to break, one of the self-adhesive held brackets had to be removed and new self-adhesive sheet material applied. While this approach to fastening the brackets to a folder is and remains desirable for a standard binder, it would naturally be desirable if the brackets could be supported mechanically (i.e., without self-adhesive) on a specially-made binder, and be readily mechanically attached and detached as needed in the event that the rotor or other parts had to be replaced.
A media folder or book binder provided with a rotor having elastic bands stretched between pins on its opposite ends has mounting brackets which are mechanically fastened to the spine of the folder. The brackets have trunnions facing inwardly toward the opposite ends of the rotor to journal the rotor. An important aspect of the invention is that each bracket is provided with a shroud which inhibits or prevents bands from disengaging with their supporting pins as a folded sheet is removed from or installed on the rotor under a strand of the band. In effect, winding-up of the bands during relative lateral movement of a sheet still occurs, but the adverse twisting affect of enabling the bands to slip off pins is prevented. The folder has straps fixed thereto and preferably formed integrally therewith at opposite ends of the folder""s spine. These straps interact with latches on the mounting brackets to firmly hold the brackets in place mechanically.
A principal object of the invention is to provide a shroud or cover on each mounting bracket, which shroud or cover extends fairly closely around and adjacent the ends of the pins on the rotor ends, thereby essentially preventing an elastic band from being displaced from its pins as a folded sheet twists during removal from or installation on a strand of a band.
Another object is to mechanically fasten the mounting brackets to the spine of a folder by providing a pair of straps that are permanently fixed to the folder.
An ancillary object is to enable installation and removal of the brackets relative to the folder by means of a simple tool such as a screwdriver.
Another object is to provide a pin-surrounding shroud on each bracket to prevent bands from slipping off their pins, and further providing an access opening in one side of each bracket to enable replacement of a broken band through the access opening.
Still another object is to simplify the alignment of parts and placement of bands on a tube forming a primary element of the rotor by extruding the tube from plastic and forming at least one aligning groove internally and one marking element externally for purposes to be described.
Other objects and advantages will become apparent from the accompanying drawings and disclosure.